Reconciling fossils with phylogenies reveals the origin and macroevolutionary processes explaining the global cycad biodiversity

A 2011 fossil-calibrated molecular analysis inferred that most sampled living cycad species originated within roughly the preceding 12 million years, but later fossil-integrated work weakens a simple globally synchronous-radiation narrative; none of these models dates the origin or fossil first appearance of Cycadales.

A species-level total-evidence model combining 321 living cycad species with 60 fossil leaf species inferred a broader high-latitude distribution through the Cretaceous and Palaeogene followed by contraction from the end of the Palaeogene to the middle Miocene; including fossils also increased inferred local extirpations from 22 to 130.

Coiro et al. combine molecular data from living cycads with leaf morphology from living and fossil taxa in a Bayesian total-evidence analysis to study cycad biogeographic history; its sampled topology is not an immutable total-group topology.

Fossil-integrated modelling supports broader high-latitude occupation followed by contraction, but ancestral areas and extirpation counts remain model-dependent.

Living cycads are terrestrial primary producers across varied habitats; the profile does not infer one fossil habitat or ecological cause for diversification.

The cited total-evidence datasets combine living cycad characters with fossil leaf taxa; leaf assignments and character coding remain explicit analytical inputs.

Cycadophyta is displayed at 330.4–0 Ma only as a total-evidence model-to-living navigation interval: 330.4 Ma is the fossilized birth–death posterior median for crown Cycadales (95% HPD 296.2–358.9 Ma), not a directly observed fossil FAD.